Presented by Settumba Mukasa and Samuel Kyamanywa (Makerere University) at the First Bio-Innovate Regional Scientific Conference, Addis Ababa, Ethiopia, 25-27 February 2013

1. Management of SPVD:
A model for production, multiplication and delivery
of clean planting material in Uganda
Settumba Mukasa and Samuel Kyamanywa
School of Agricultural Sciences, Makerere University,
P.O. Box 7062, Kampala, Uganda.
First Bio-Innovate Regional Scientific Conference
United Nations Conference Centre (UNCC-ECA)
Addis Ababa, Ethiopia, 25-27 February 2013
Cassava Potato Sweetpotato Bioinnovate Consortium

2. Background
• Diseases of viral origin cause great yield loses in sweetpotato, an
important and widely grown tuber crop in Uganda.
• Currently, sweetpotato virus disease (SPVD) is the most devastating
disease of sweetpotato in Uganda, ECA and worldwide.
• SPVD is caused by duo infection and synergistic interaction of two
viruses namely the aphid-borne Sweet potato feathery mottle virus
and the whitefly-borne Sweet potato chlorotic stunt virus.
• SPVD causes yield losses of over 58 % and extinction of susceptible
varieties including orange fleshed varieties that have been developed
to fight vitamin A deficiency in tropical Africa.
• Use of planting material not tested for viruses is the main means by
which SPVD is spread.
• The situation is further complicated by lack of adequate quantities of
quality planting material and an efficient distribution system in ECA.

3. Subsistence Vs commercial growing of sweetpotatoes

4. Previous Research Progress at MAK
• Progress has been registered at MAK in Uganda
under the BIOEARN/Bioinnovate Programs and in
partnership with CIP/HarvestPlus, and ASARECA
programs in the areas of:
• i) diagnostic protocols for the major viruses of
sweetpotato in Uganda
• ii) identification of elite and SPVD tolerant varieties,
• iii) developing tissue culture based systems for virus
elimination,
• iv) optimising protocols for rapid in vitro sweetpotato
multiplication,
• v) developing a model for production, multiplication
and delivery of quality tested planting material, and
• vi) identifying policy issues that would ensure
sustainability of a model for production and delivery
of quality planting material.

5. Rationale
• Despite the successful dissemination of elite varieties (including
OFSP) many of them succumbed to the devastating SPVD.
• Lack of good supply of virus free planting material does not allow
sustainable cultivation and dissemination of elite varieties.
• Putting in place a sustainable system for production and delivery
requires: appropriate varieties, a battery of bio-techniques, resources
to create awareness among growers and potential investors, and
relevant policy guidelines.
• Given the initial high costs and un-predictable market forces, there
was need for Piloting Public-Private-Partnership in sweetpotato vine
multiplication

6. Objectives
The main objective of this research was promote adoption of using
virus free sweetpotato planting material sustainably through piloting
an appropriate model involving private and private actors.
This pilot phase is envisaged to develop into a large-scale
decentralized system for sweetpotato vine multiplication.

7. The Approach
• In this MAK-BIOCROPS-HarvestPlus partnership, MAK carried out
activities on the rapid multiplication of virus tested sweetpotato
planting using TC.
• Low cost approaches
• Locally avaiable materials
• MAK provided virus free TC derived sweetpotato plantlets/cuttings to
BIOCROPS (U) Ltd, which showed interest in commercial
multiplication of certified (basic) disease-free planting material of
existing and new varieties.
• CIP/HarvestPlus is poised to deliver the expanded volumes of clean
vines to farmers through vine multipliers/farmer groups from whom the
farmers buy.
• Creation of awareness along the quality sweetpotato planting material
value chain (3 to 4 value chain actors).

8. Elite varieties for pilot multiplication
Orange fleshed: White fleshed: Bioinnovate clones
(20 cones under farmer
participatory evaluation)
Ejumula Dimbuka
Kabode (SPK 004/6/6) NASPOT 01
Kakamega (SPK004) New Kawogo
Vita (SPK 004/6) Semanda

9. Tissue Culture Research at MAK TC LAB:Optimisation of protocols for in
vitro rapid multiplication of sweetpotato varieties (New and SPVD tolerant
varieties, and OFSP varieties)
A) In vitro rapid multiplication of sweetpotato in one of the culture rooms in the Makerere
Plant Tissue Culture Laboratory. B) In vitro sweetpotato shoot multiplication, root
induction and hardening in re-cycled baby food jars.

10. Weaning of sweetpotato in the
traditional weaning chambers as for
bananas could only registered up to
50% survival rate. However, using
recycled mineral water bottle though
more cumbersome, registered over
95% survival.
Weaning and hardening could
also be carried out in bottles to
raise mini vines for micro-
cuttings and establishment in
the screenhouse.

11. Further hardening of tissue culture derived plantlets in plastic pots (A) or
cups (B) after weaning in bottles.

12. Nursery multiplication of elite sweetpotato clones in a
screenhouse at MUARIK (Kabanyolo).

13. Laboratory space
General lab (M2) 50
Transfer room (M2) 60
Laminar chambers (#) 5
Growth room (M2) 110
R & D Labs (M2) 46

14. About BIOCROPS (U) LTD
• A Ugandan-based Agricultural company
• Established in 2008
• Provides high quality planting material, plant products and
solutions
• Located at Kabaga, Wakiso District, 15 Km Bombo Road

15. Nursery facilities
Insect proof screen house
Nuclear material
75 sqM floor

16. Vine multiplication
200 sqM floor
Banana Nursery 375 sqM floor

17. Annual production capacity
200,000 sweetpotato vines (500
vine bags; UGX 10,000,000)
200,000 banana plan

18. Creating Awareness:
working through with
vine multipliers
www.tclab.mak.ac.ug

19. Creating Awareness: working through with vine multipliers

20. Sweetpotato QPM Value Chain Actors
1: 10 : 100
Farmers:
Xn X 2-4 X 1-2
Zone 1
TC Screen- Open Zone 2
Lab house field(s) Zone 3
Zone 4
∞ 3 months 3 months
Capacity: 40,000 TC plants (4,000 Acres)
Virus test 100% 99% 95% 90%
Season 02 September December March
Season 01 March June September

21. 3 – Tier level system
for rapid multiplication
of quality sweetpotato
planting material

22. Key results and implications
• Protocol for rapid in vitro multiplication of sweetpotato
• A 3-tier production, multiplication and delivery model was piloted in
Uganda.
• Levels of awareness created among some commercial vine
multipliers.
• A public-private patnership (MAK-BIOCROPS-HarvestPlus) created,
and this could used to further advance promotion of QPM.
• Growers would access field multiplied materials from vine multipliers
in their respective growing zones.
• We have attracted other partners: ASARECA (baseline, protocols),
ILRI (Passionfruit), BMGF (Cassava virus diagnostics).
• However, for the sustainability of the sweetpotato seed system,
there is need to have policy support (MAAIF/ASARECA).

23. Looking Forward
Thank You